Those are reducers, not bushings. DU bushings were used on RS shocks, manitou shocks and old fox shocks. They were often delrin-urethane or teflon-impregnated brass or some other wear material. IGUS bushings are what newer fox shocks have, a hard polymer that wears and provides lubrication when it rotates.Anyone have a part number for the DU bushings for a Mach 429 Carbon? Manual says 22mm front and 36mm rear, but I can't find a match.